package com.itheima.Jiuye02Demo01;

public class Bijiben {
    public static void poweron(){
        System.out.println("笔记本开机");
    }
    public static void poweroff(){
        System.out.println("笔记本关机");
    }
    public static void useDevice(USB u){
        u.open();
        u.close();
    }
}
